Add support for eth_signTypedData and personal_signTypedData RPC call

[Bhargavasomu]

What was wrong?

Related to Issue #1241

How was it fixed?

The eth_signTypedData was created by mimicking the eth_sign implementation throughout the codebase.

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[Bhargavasomu]

@kclowes I am getting the following error in most of the test cases on circle ci.

ValueError: Unknown RPC Endpoint: eth_signTypedData

I even tried by replacing eth_signTypedData with account_signTypedData, but I am getting the same error. Is there something I am missing? Thankyou.

[kclowes]

@Bhargavasomu It doesn't look like eth_signTypedData has been released yet for Geth, so we can add an xfail to those tests. An xfail example can be seen here:

web3.py/tests/integration/go_ethereum/common.py

Line 20 in cba9538

pytest.xfail('Needs ability to efficiently control mining')

For Parity, it looks like we'll have to add the --jsonrpc-experimental flag (from this PR) when we start the parity node for the tests.

[Bhargavasomu]

@kclowes The docs have been updated now too. Please review and let me know.

[kclowes]

I left a couple nitpicky comments, but this is looking really good.

I have one point to clarify: Is it true that the reason that we are doing so much validation of the typedData in eth-account and not here is because eth-account can be used without connection to a node?

Thanks!

[Bhargavasomu]

@kclowes yes that is why I didn't put up the validations as part of web3.py.

1. It can be used without a connection to the node.
2. Moreover I feel that all such validations should be done on the node side, rather than at web3 side. (Please correct me if I am wrong.)

I have addressed the other issues. Please review once more. Thankyou.

[Bhargavasomu]

@kclowes I have addressed the issue about skip_if_testrpc. Please review. Thankyou.

[kclowes]

Looks good to me! Thanks @Bhargavasomu! @pipermerriam do you have any other feedback here?

[Bhargavasomu]

@pipermerriam is this good to merge with?

[tuxxy]

Bump on this PR? We (@nucypher) are currently blocking on this and this would alleviate the pressure a ton.